Electric welding



Patented June 9, 1936 UNITED STATES amm ILIOl'l-IO WELDING LloydTheodore Jones. and Maynard Arthur Itotermnnd. Manley.

Kennedy,

No Drawing Application Ootobc 0, loss, Serial m. .10

29 Claims. (Cl. 810-10) This invention relates to electric welding.

Among the various ways in which electrical energy has been convertedinto heat for the welding of metals, the arc process (which itself takesseveral forms) is the one most generally practiccd. A typical example ofarc-welding is its use to join the abutting edges of steel plates. Inthe metal-arc variation of the arc process, molten metal, provided bythe melting of a metal wire or rod of suitable composition, isintroduced between the abutting edges of the plates. and the latter arefused sufliciently to permit the added metal to coalesce with the metalof the plates so that, on cooling, a structurally strong bond results.The requisite heat is developed, as the term "are process" implies, bymaintaining either a direct current or an alternating are between theparts to be welded, connected to one side of the power line, and thewire or rod used to supply the molten metal, connected to the other sideof the power line. The abutting plate edges are usually beveled to forma trough for receiving the molten metal, thereby facilitatingcoalescence of the added metal with the plates throughout the thicknessof the latter.

The simplicity of bare wire-electrode welding recommends it above allother methods, but the metallurgical and physical properties of metaldeposited in this simple manner are usually so poor that the method isunsuitable for many applications.

In order to avoid certain diiiiculties encountered in bare metal arcwelding, it is customary to protect the freshly deposited molten metalwith a blanket of molten metal compounds (usually compounds of thealkali or alkaline earth metals). The material used for forming thisblanket is called the "flux". The usual method of providing a fluxblanket on the weld is to encase the welding rod or wire (usuallyreferred to as the electrode) in an adherent sheath of solid flux, andthis gives rise to other difliculties. The sheath is usually fragileand. being nonmetsllic in nature, is nonconductive when cold, so thatelectrical connection must be made with the electrode at points baredfor that purpose at intervals at variable distances from the weld,thereby imposmg an additional burden on the automatic regulating deviceswidely used in welding. When the bared sections reach the melting nonemetal of inferior quality is deposited. The current must pass through avariable length of rod, the length between the are and the contactpoint. heating it suillciently to crack off the flux covering andfurther to add an IR-drop to the arc voltage. This IR-drop is notconstant in magnitude but varies according to the position of thecontact point relative to the arc. The machine. unable to discriminatebetween arc voltage and electrode drop, cannot maintain the constant arclength so necessary to successful welding unlesscompensatorymeansareresortedto. Thssediiilcultics therefore limit theenergy which may be expended in the are. We are not aware of currentvalues in excess of about 600 amperes being used in this manner ofwelding.

For good welding a homogeneous deposit of metal is indispensable. Inmetal-are welding it is found that the diiilculties involved in securinga homogeneous deposit are multiplied as the thickness of the depositincreases, so that, if thick plates are to be welded. it becomesnecessary to make several traverses or "passes", adding a layer of metaleach time until the necessary thickness is attained. This method ofoperation is obviously time-consuming, the more so since it is usuallynecessary to chip oil the cover of solidified flux on one deposit, andpeen the metal, before another deposit can be superimposed. It alsocomplicates the stresses set up by contraction of the metal in thecooling weld, and the resulting distortion of the welded parts.

There is another known means of applying protective flux. It consists inutilizing a thick coating of finely divided material, a flux, whichcovers the seam to be welded. The welding electrode. which is a barewire of suitable composition, is fed down by conventional feeding meansand the arc is struck under this powdered iiux. The electrode istraversed at a contant rats along the path to be welded. Directcurrentis applied at a voltage of about 30 volts with a current up to about 900amperes. The flux used in this system has been a natural clay ofapproximately the composition used in making brick. The following is atypical-analysis of such a flux: 50.8% 810:: 18.86% AhOa: 4.34% l' esOs:0.00% CaO: 8.00% Mn; 3.03% Fe. Although this method retains theadvantage of feeding current continuously to a bare wire at a pointadjacent to the weld, the weld metal deposited thereby is seriouslydeficient in quality. A weld made by this method may have ample strengthfor certain purposes, but itissoporousthatitcanhardlybesaidtobesatisfactory. It is. therefore.customary to hand-weld on the bottom side to insure superficial freedomfrom holes. It has not been found possible to extend this method beyond59 inch plate and there is no immunity from undesirable porosity in anythickness. Moreover, the vigor of the arc submerged under this fluxprojects a continuous cloud of material into the atmosphere. An evidenceof the amount of gas that is emitted by a flux of this nature isafforded by the fact that the welders very frequently wear gas masks toprotect themselves from the dust. Since the dustisthrownupbygasthstisevolvedfmmtheflux and the weld metal, it is notsurprising that gas holes should be found in the metal of the weld.

An object of the present invention is to avoid the disadvantageousfeatures cited above, and to provide a process by which even thickplates can be strongly and rapidly electrically welded, in a single passor in a plurality of passes, with a weld of which the density andphysical prope ties are at least equal to those of the parent metal.Another object is to provide a process in which heavier welding currentscan be used and the rate of welding accelerated. A further object is toovercome the dihlculties which, in prior processes, are caused by theinherent instability of an electric arc, its liability to beextinguished by a variety oi dventitious causes, and the difficulty,especially in automaticmachines, of reestablishing the are when ithas-been extinguished. Another object is to avoid the necessity for aflux sheath on the electrode. otheroblects of the invention will becomeapparent as' the description of our invention proceeds.

We have discovered a novel process for electric welding wherein thenecessary heat is generated by the of a heavy electric current between ametal electrode (usually bare) and the metal plates or similar objectsto be welded, the electrode being out of mechanical contact with theobjects and the current being carried across the gap between theelectrode and the objects by and through a conductive melt or weldingcomposition having appropriate electrical resistance properties. Theheat thus generated melts successive portions of the electrode and themolten material is deposited as weld filler material. The weldingcomposition serves as'an active instrumentality, or welding medium,inasmuch as it provides heating means, controls the rate, penetration,and quality of welding, purines the molten metal, and protects themolten metal.

A large number of experimental welds which a we have made support theconclusion that the properties of a successful welding composition forthis method of welding are these:

(i) The chemical reactions between the components of the weldingcomposition must be completed before it is used in welding. Failure inthis regard most surely invites porosity.

(2) It must be capable of controlling the penetration and the width ofthe weld.

(8) Its fluidity at welding temperatures must be such that it will notbecome entrained with the molten metal.

(4) It must consist of chemicals which are not detrimental to theproperties of the steel, and

(5) It must be readily removable from the finished weld.

The composition of the welding medium is of the utmost importance. Theparticular composition that is to be used is determined by the qualityand thickness of the metal plates to be welded, by the current andvoltage to be used. and by the properties it is desired to impart to theweld metal.

we have used calcium silicate and silicates of sodium, barium, iron,manganese, cobalt, magneslum, nickel and aluminum, both in binary andternary combinations, in various proportions. we have also used calciumtitanate and various titrno-silicatos. those being used when it isdesired to introduce titanium into the weld metal. While a number ofthese conductive welding compositions are more or less efficacious inour proccan, we prefer to use silicates of the alkaline earth metals,such as calcium silicate, and we also prafer to add to these silicatesminor proportions of alumina and of a substance adopted to lower themelting point, for example, a halide salt.

More specifically, the welding composition prelerably comprises, as itsprincipal ingredients, silica (810:), at least one basic constituentconslsting of an alkaline earth such as lime (CaO) or esia (MgO) or amixture thereof, and alumina (A1101). The silica and basic constit-'uent are in approximately the proportions theoretically required toform metasilicates, although a substantial excess of silica ispermissible and frequently advisable. For example, if the basicconstituent is lime, the proportions by weight will be approximately 0.7to 1 part of Ca() to 1 part of SlOa; and if magnesia is substituted forpart or all of the lime, the silica is increased accordingly, so as tomaintain about the same stoichiometric proportions. The alumina formsabout 1% 'to 8%, by weight, of the welding composition, and preferablyabout 4% to 6%. In order to cause the energy to be distributed over alarger area we add, in various minor proportions, say 6%, a materialcapable of reducing the energy concentration and thereby widening theweld. A preferred material for this purpose is a halide salt such ascalcium fluoride.

' The basic constituent preferably consists chiefly of lime and magnesiain approximately the proportions of three parts of CaO to one part ofMgO, by weight; but other proportions are useful and within theinvention. Basic materials other than lime or magnesia, for exampleoxides of manganese, titanium, or the alkali metals, and known fiuxingagents such as borax or boric acid. may be added in moderate amountswithout greatly changing the essential characteristics of the weldingcomposition, but it is important that the composition be substantiallyfree'from iron oxides uncombined with other ingredients of thecomposition (by being preiused with such ingredients, for instance), andfrom materials (such as carbonates or moisture) which evolve detrimentalamounts of gas or vapor at welding temperatures.

It is possible, and may at times be desirable, to include in the weldingcomposition materials which are transferred to the weld filler materialduring the welding operation and appear in and modify the properties ofthe completed weld, for example: ferromanganeac, ferrccilicon,ferrochromium. calcium molybdaie. carbon, or reducible chemicalcompounds thereof.

In a specific instance, we fused together 50 pounds of calciumcarbonate. 9.4 pounds of magnesium oxide, and 40.5 pounds of silicauntil the reaction was complete. The materials used were of the purestquality used in the ceramic industries, but the fused product showed thepresence, on analysis, of about 5% alumina. The fused material wascooled and granulated, and to each pound, one ounce of fluorspar wasadded. The material was then ready for use to form the conductive meltwhich is the principal feature of our process.

welding compositions which have been u successfully and which serve asrepresentative examples within the invention have the followinganalyses, by weight:

I II III IV 29.5 IiJi ms 40.12 3.1 .01 It 0.89 86.4 52.40 a7. 5194 6.4Lil i." 5.80 Low 0.11 0.8 on

Beforeusaahoutipartofcaleiumiiuorldewasaddedtollipartabywcishaoi'eachoftheabove compositions.

The chemical condition of the welding composition or medium isimportant: the acidic and bssic constituents should be reacted. thecomposition should be substantially anhydrom and free from gases, andall reactions which would evolve deleterious amounts of gases duringwelding should be substantially completed. before themediumisusedintheweldingwoccss. These conditions are suitably attainedby prefusing a mixture of the constituents, preferably in an electricfurnace. Certain relatively volatile but chemically stable constituentssuch as calcium fluoride may be added to the medium either before orafter the other ingredients have been fused and cooled. The carbonatesof calcium or magncslum may be substituted for the oxides, of course, ifthe ingredients are prefused.

The physical condition of the welding composition is likewise of theutmost importance. If the molten medium is rapidly solidified bycooling, before grinding and use, more homogeneous and solid welds maybe produced than when it slowly loses heat and solidifies. The fusedcomposition is preferably cast as a relatively thin layer againstemcient cooling orchlllingmeanssuchasacold heavy plate or block ofmetal,'or a water-cooled chill plate, rather than as a large ingJt. Itis preferred that the rate of cooling be such that substantially all ofthe solidified welding composition is characterised by a vitreousfracture.

Inpracticingom'processtheplatutobewelded are arranged as for metal openarc welding. The edges are preferably beveled, but this is lessnecessary than with arc welding because the "penetration" and width ofthe weld (the extent to which the edges of the plates are fused duringthe welding) is dictated by the composition of the flux and the voltageand current employed, and can be closely controlled in our process.Means for backing-up" the seam during welding is preferably used.

When a weld is to be made between beveled edges the operation is startedby filling the groove. space, or gap between the edges of the objectswith the welding composition, preferably in powdered or granular form,and a substantial additional quantity of the composition is heaped upalong the groove, thereby overfilling the said groove. After the weld iscompleted. that portion of the composition which has not been fused maybe removed, by a vacuum system for example, collectedandreused.Theportionwhichhasheen fusedmaybeliftedfrcmtheweldeaposlnga clean anduniform weld surface. The fused material may be reground and reused, anyvolatile constituents, such as halides. being replaced. However, undersome circumstances the reuse of the welding composition results in asomewhat inferior weld, probably because the composition has picked upimpurities during its use.

According to the welding method of the invention, the end of the weldingelectrode, which is preferably a bare metal electrode. is first insertedinto the welding composition. Since the composition is nonconductivewhen cold. a conductive path for the welding current is provided bybridg- I ing the gap between the electrode and the work with, forexample, a sliver of graphite or a wad of steel wool. The power is thenapplied. the weldingcompositionislocallyheateduntilitfuses and becomesconductive, forming a subsurface pool, and immediately thereafter theend of the electrode begins to fuse and the molten metalbeginstodepositinthesroove,displacingthesubmrfscepooloffusedweldiogcomposition. Atthe sametimetheedgesoftheobiectsbeingweldedbesintofuseandtocoalesce withthedeposited metal. The electrode is thenfed toward the work and moved along the seem at an appropriate rate.preferably by a mechanical device which may besimilartothosewhichareeatensivelyusedin openarcweldiug,andtheweldingpmoeedswithoutinterrupticn.

The welding proceeds under a protective layer of the compositionunobtrusively. There is prac tically no puffing or visible displacementof the welding medium, no visible sparking, and, indeed. scarcely anyexternal evidence that a weld is being made. The weld is ordinarilycompleted in one pass. even in thick plate. The welding composition infront of the electrode remains unfused. while the fused compositionrises to the top of the completed portion of the weld and solidifies.Even this effect is scarcely visible because of the use of an excess ofthe welding composition which remains unfused and covers the fusedcomposition and metal.

It is possible in our process to use either alternating or directcurrent, or direct current superimposed on alternating current.Alternating current alone is preferred.

The results attained are influenced, as in open arc welding. by thepotential or voltage difference between the electrode and the work, bythemagnitude of the welding current, by the size of the electrode. andby the rates at which the electrode is fed toward the seam and traversedalong the scam. Assuming a constant welding speed, the welding voltageand current vary with the plate thickness, each being a functionthereof. For example. we may use a welding voltage of about 36 volts anda welding current of about 1500 amperes when welding together steelplates about one inch thick using a bare welding rod about inch indiameter and a welding speed along the scam of about 8 inches perminute. The welding current may rise to 2000 amperes or more, and withsuch heavy currents plates 1.5 to 2 inches thick may be welded in onepass at a rate of 6 or '1 inches per minute.

The preferred welding current is a function of several factors includingthe diameter of the electrode, the rates of penetration, deposition ofmetal, and travel along the seam, the penetration of the work piece, andthe composition of the flux. It is a characteristic of the inventionthat, for an electrode of a given size, the preferred current is fargreater than can be used successfully in processes heretofore known. Thefollowing table indicates the order of magnitude of the current in theold and new processes, for the purposes of comparison, but it will berealised that the invention is not limited to the use of the currentvalues shown.

Currant ampares llsetroda diameter inches The invenmm Old methods a wowto s l to to In welding very heavy plate it advantageous to use twopasses rath ocemanotdirectlyimdertbeeieetrodemtbaek of it, and thereappear to be liquid currents (posaibbeamedbytheao-caliedpincheflect")whichcauaethesuriaceottheresistivecmnpoaithe energy dmsiis on the partsto be welded may be satisfactorily controlled and the productill: 01 asound weld may be assured.

Thisapplimtimisacontinuatiominpartoi our prior applications SerialNumbers 657,836 and 705m, respectively, died February 21, 1933 andJanuary I, ma.

We claim:

1. The process 02 electric welding whichcompriaesthestepsotiuxtapoaingaoelectrode andaconductivemembercnwhichmetalietobe deposited: establishing between saidmember and said electrode a conductive path of a high-reaistance melt oichemically stable fusible material having at welding temperaturessubstantially the fluidity and electrical conductivity 01 a i'uaihiesilicate. and substantially tree from substances capable of evolvinglarge amounts of gases during welding; passing through said melt anelectriccmrentoisumcientstrengthtomaim tain its conductivity,progressively melt the required amount of metal, and cause the resultingmolten metal to coalesce with said member; and maintaining said melt incontact with said electrode throughout the welding operation to avoidthe formation of a substantial air-conducted electric are between theelectrode and the said conductive member.

2. The method 01 electric welding by melting ametal electrode,depositingthemetalsomelted upon a metal work piece. and coalescing said meltedmetal with adjacent fused metal of said work piece, which methodcomprises supplyingheatioraaldweidimbypassinganelectriccurmgatadensityohmwardsct about2000amperm per inch of diameter of said electrode,substantiailywholbthroughapooloi'silicatemsed in situ, without theformation of any substantial gas-conducted electric are.

3.Themcthodoielectricweldingbymeltingametalelectrode,depositingthemetalsomelteduponametaluorkpleceandcoaleecingsaid meltedmetalwithadiacentiusedmetaloisaid workpiece,whiehmethodcomprises supplyingheati'orsaidweldinghypassinganelectrieeurrenttrunaaideiectrodetosaidworkpiecethroughameednonmetailicmaterialwhichactsasahigh-resistanceconduetoratweldingtemperatmesandwhiehdoesnotevolvesubrtm tial constantcontnctwithaaidelectrode andwork toavoidthei'ormation oiasubstantiai-cmduetedelectricucbetweentheeiectrode piece. methodolelectricweldingbymelting electrodedepositingthemetalaomelted ametnlworkpieceandcoalescing ma tedmetalwithadiacenttusedmetalotsaidpiecewhichmetbodcomprises supplying l ywnaanelectriccurfrom saidelectrode to said work piece apooloinonmetallicmaterialiusedinwithoutmaterialevolution 0! gas, and mainsaid pool in constantelectrical contact th said electrode and work piece to avoid theormation of a substantial air-conducted electricambetwerntheelectrodeandworkpiece; saidnon-metallicmnterialbeingonewhichactsas a high-resistance conductor atwelding temperatunes.

L'lhcproemotelectricweldingwhichcomm'hcetbeatepaotjuxmpoaingametaleleeuodeandacmduetivemqnberonwhiebmetalisto be deposited: establishing betweensaid member and said electrode a conductive path of a high-resistancemelt of fusible silicate, substantiaily free from substances, such asuncombin iron oxide, capable ofevolving large amounts 0 gases when fusedin contact with the metal to be deposited; passing through said melt anelectric current of sumcient magnitude to maintain the conductivity,progressively melt the said electrode and cause the resulting moltenmetal to coalesce with said member; and maintaining said melt in contactwith said electrode and member throughout the welding operation.

8. The process of electric welding which comprises the steps ofjuxtaposing a metal electrode and aconductive member on which metal isto be deposited; establishing, between said mem-- bet and said electrodea conductive melt comprising an alkaline earth metal silicate, alumina,and an alkaline earth metal fluoride, substantially free fromsubstances, such as uncombined iron oxide, capable of evolving gaseswhen fused in contact with the metal to be welded; passing through saidmelt an electric current of sumcient magnitude to maintain theconductivity, progressively melt the said electrode and cause theresulting molten metal to coalesce with said member; and maintainingsaid melt in contact with said electrode and member throughout thewelding operation.

"I. The process of electric welding which comprises juxtaposing a metalelectrode and a metal member on which metal is to be deposited from saidelectrode; filling the gap between said electrode and said member with afinely-divided, unbonded, nonmetallic material which is fusible atwelding temperatures; heaping an additional amount oi said material'above said gap so as to submerge said electrode for a substantialdistance; fusing a portion of said material in said gap to render thematerial electrically conductive: progressively moving said electrodealong said member; passing through the circuit comprising said eectrode, fused material, and work piece an electric current sufiicientto melt successive portions of said electrode and said metal member andto maintain a pool of said nonmetallic material in contact with saidelectrode and adjacent to and covering the molten metal; andsimultaneously maintaining said fused pool, said end of said electrode,and said molten metal submerged under a quiet layer of said nonmetallicmaterial.

8. The mehod oi uniting metal work pieces by fusion depositing addedmetal from an electrode and coalescing such added metal with adiacentfused metal of the work which comprises juxtaposing the work pieces tobe united so that a space is provided therebetween at the line ofintended union, overfiiling said space with unbond ed particles of aprefused solidified and ground material capable of refusion in situ andactive when fused to cleanse the fused depositing metal of an electrode,such refusion and cleaning occurring without substantial apparent gasevolution, and traversing said space with the end of an electrode of themetal to be deposited, said end being submerged in said material, whilepassing current between the work and the electrode of a magnitude tomaintain a localized subsurface pool of said material fused and to fusethe electrode at a rate to effect deposit of sumcient metal therefrom todisplace said pool and substantially 1111 said space as traversed, andmaintaining a substantiallymrietsurfacelayerofsaidnnbonded particlesover the area of fusion.

9. The method of uniting metal work pieces by fusion depositing addedmetal from an electrode and coaluing such added metal with adjacentfused metal of the work, which comprises juxtaposing the work pieces tobe united so that a space is provided therebetween at the line ofintended union, traversing said space with an electrode of the metal tobe deposited while passing an electric current between the work and theelectrode of a magnitude to fuse the latter at a rate to eifect depositof sufllcient metal therefrom to substantially fill said space astraversed, bridging the fusing end of said electrode and the adjacentfused local area of the work with a pool of material fused in situwithout substantial gas evolution, said fused material beingelectrically conductive and active to cleanse the fused metal of theelectrode and the work, and simultaneously maintaining said fused pool,said end of said electrode and said local area of the work submergedunder a quiet protective layer of unbonded particles.

10. A process of electric welding which comprises the steps ofjuxtaposing a metal electrode and a conductive object on which metal isto be deposited, placing between said object and said electrode a highresistance conductive path consisting of a prefused welding composition,and passing through said electrode, welding composition, and object anelectric current of sufficient magnitude .to establish and to maintainthe -conductivity of said composition, to melt successive portions ofsaid electrode, and toupause the resulting molten metal to coalesce withsaid object; said welding composition being substantially free from\mcomblned iron oxide and from materials which evolve gas at weldingtemperatures and.having for its principal ingredients silica, lime,magnesia, and alumina, and also containing a minor proportion of ahalide salt. the silica, lime and magnesia being in approximately theproportions of 2'! to 38 parts lime, 9 to 16 parts magnesia, and partssilica, and the alumina being about 4% to 6% of the composition.

11. A process of electric welding which compr e the step of forming aconductive highresistance melt, containing a major proportion ofalkaline earth metal silicate and substantially free from uncombinediron oxide, on a metal part to be fused: andpassing an electric currentthrough a circuit comprising said melt and said metal part.

12. A process of electric welding which comprises the steps ofjuxtaposing a metal electrode and a conductive member on which metal isto be deposited; establishing between and in contact with said memberand said electrode a conductive melt of fusible silicate. substantiallyfree from substances capable of evolving gases when fused in contactwith the metal to be deposited; and passing through said melt anelectric current of sufficient magnitude to maintain the conductivity,progressively melt the said electrode and cause the resultingmolten'metal to coalesce with said member.

13. A process of electric welding which comprises the steps ofjuxtaposing a metal electrode and a conductive member on which metal isto be deposited: establishing between and in contact with said memberand said electrode a conductive path of high-resistance melt containinga major proportion of silicate and substantially free from uncombinediron oxide: and passing along said conductive path an electric currentof sufllcient magnitude to maintain the conductivity, progressively meltthe said electrode and cause the resulting molten metal to ocaleme withsaid member.

is. A process of electric welding which comprises the steps oijuxtaposing a metal electrode and a conductive member on which metal isto be deposited; establishing between and in contact with said memberand said electrode a conductive melt comprising an alkaline earth metalsilicate and an alkaline earth metal fluoride; and passing through saidmelt an electric current of sufficient magnitude to maintain theconductivity, progressively melt the said electrode and cause theresulting molten metal to coalesce with said member.

16. A process of electric welding which comprises the steps ofjuxtaposing a metal electrode and a conductive member on which metal isto be deposited; establishing between and in contact with said memberand said electrode a conductive melt containing a major proportion ofalkaline earth metal silicate and substantially free from uncombinediron oxide: passing electric current through said melt to maintain theconductivity and progressively melt said electrode: and moving saidelectrode along said member while maintaining the current and theconductive melt therebetween.

16. A process of electric welding which comprises the steps ofjuxtaposing a metal electrode and a conductive member on which metal isto be deposited; establishing between and in contact with said memberand said electrode a conductive melt of fusible silicate substantiallyfree from imcombined iron oxide: and passing through said melt anelectric current of sumcient magnitude to maintain the conductivity,progressively melt the said electrode and cause the resulting moltenmetal to coalesce with said member.

17. A process of electric welding which comprises the steps ofjuxtaposing a metal electrode and a conductive member on which metal isto be deposited; establishing between and in contact with said memberand said electrode a conductive melt of an alkaline earth metal silicatesubstantially free from uncombined iron oxide; and passing through saidmelt an electric current of sufficient magnitude to maintain theconductivity, progresively melt the said electrode and cause theresulting molten metal to coalesce with said member.

18. A composition for electric welding containing a major proportion ofalkaline earth metal silicate. and being substantially free fromuncombined iron oxide and from substances capable of evolving gasesunder welding conditions.

19. A composition for electric welding containing a maior proportion ofcalcium silicate, and being substantially free from uncombined ironoxide and from substances capable of evolving gases under weldingconditions.

20. A composition for electric welding containing a fluoride and a majorproportion of alkaline earth metal silicate. and being substantiallyfree from uncombined iron oxide and from substances capable ofevolvinggases under welding conditions.

21. A composition for electric welding containing a fluoride and a majorproportion of calcium silicate and being substantially free fromuncombined iron oxide and from substances capable of evolving gasesunder welding conditions.

22. A flnely-divided unbonded fusible electric welding compofltioncontaining a fluoride and a major proportion of an alkaline earth metalsilicate.

'13. A finely-divided unbonded fusible composition for use in electricwelding employing a bare metal electrode as a source of weld metal, saidcomposition being substantially free from substances capable of evolvinga detrimental quantity of gas under welding conditions and containingcalcium fluoride and a major proportion of one or more alkaline earthmetal silicates.

24. A fluxing material for electric welding comprising metallic silicateand calcium fluoride.

25. A composition for electric welding comprising fluorspar, magnesiumsilicate.'and calcium silicate, the latter silicate being present inpredominant proportion.

26. An electric'welding composition which is conductive when molten,consists chiefly of silicates, and contains about 1% to 8% alumina.

27. A prefused electric welding composition which is conductive whenmolten and the principal constituents of which are alkaline earth metalsilicates, said composition containing about 1% to 8% alumina and beingsubstantially free from materials such as uncombined iron oxide whichevolve large volumes of gas or vapor at welding temperatures.

28. A prefused electric welding composition which is conductive whenmolten, is substantially free from uncombined iron oxide and frommaterials which evolve large amounts of gas at welding temperatures, andthe principal ingredients of which are silica. alumina. and at least onebasic ingredient of the group consisting of lime and magnesia, the basicingredients being present in an amount between about 70% and about 100%of that theoretically required to combine with all of the silica presentto form metasilicates, and the alumina being about 2% to 8% of thecomposition; and said composition having as a minor ingredient analkaline earth metal fluoride.

29. A prefused and comminuted electric welding composition which has avitreous fracture, is conductive when molten. and consists substantiallyof silica, lime. magnesia. alumina, and calcium fluoride, the silica,lime, and magnesia being in approximately the proportionsof 27 to 38parts lime, 9 to 16 parts magnesia, and parts silica. the alumina beingabout 4% to 6% and the calcium fluoride being about 6% of thecomposition; said composition being substantially free from uncombinediron oxide and from materials which evolve gas or vapor at weldingtemperatures.

LLOYD THEODORE JONES. HARRY EDWARD KENNEDY. MAYNARD ARTHUR ROTERMUND.

Disclaimer 2,043,960.-Lloyd Theodfore Jone: Harry Edward Kennedy and Mard Arthur Rolermund, Berrkele Caiif. ELECTRIC WELDING. Patent ated June9, 1936. Di'sclaimer ed Man-15, 1949, by the sssignee, The Linde AirProducts Company. Hereby enters this disclaimer to claims 1 to 17inclusive, and claims 24, 26, 27, 28, and 29 of said specification.

[Ofimal Gazette April 19, 1949.1

Disclaimer 2,043,960.Ll0yd Theodora Jones, Harry Edward Kennedy andMaynard Arthur Rotermund, Berkeley, Calif. ELECTRIC WELDING. Patentdated June 9, 1936. Disclaimer filed Mar. 15, 1949, by the assignee, TheLinda Air Products Company. Hereby enters this disclaimer to claims 1 to17 inclusive, and claims 24, 26, 27, 28, and 29 of saidspecification.

loam! 0mm April 19, 1949.]

